// 2025/5/10
// 计算字符串的编辑距离

#include <iostream>
#include <vector>
using namespace std;

int main() {
    string str1, str2;
    cin >> str1 >> str2;
    int len1 = str1.size(), len2 = str2.size();
    vector<vector<int>> dp(len1 + 1, vector<int>(len2 + 1, 0));
    for(int i = 1; i <= len1; i++) dp[i][0] = i;
    for(int j = 1; j <= len2; j++) dp[0][j] = j;
    for(int i = 1; i <= len1; i++)
    {
        for(int j = 1; j <= len2; j++)
        {
            int tmp = dp[i - 1][j - 1];
            if(str1[i - 1] != str2[j - 1])
                tmp++;
            dp[i][j] = min(dp[i - 1][j], dp[i][j - 1]) + 1;
            dp[i][j] = min(dp[i][j], tmp);
        }
    }
    cout << dp[len1][len2] << endl;
    return 0;
}
// 64 位输出请用 printf("%lld")